Electric switch



Dec. 9, 1947. R. P. DIMMER ELECTRIC SWITCH Filed Sept. 11, 1945 o mmzwuwm INVENTOR. ROBERT P. DI MMER ATTORNEYS Patented Dec. 9, 1947 t ee wen

E bert Automatic Elec erefietueeeeiee ze l s e 1.9 cabins rimea This invention relates .to electric. switches. and more .particu1ar1y..to -a motor. .driven switch .suitable fortuseinsan. electric circuit such as a directionfinden.

' In.directionfindersithasbeen proposed to rev verse. the connections .to the. antenna. andv concommitantiy reverse.theconnections to an indicatingsmeter, Various methods. have. been sug, gested and employedtb provide such reversal of connections. including vacuum .tube switches and mechanical switches. For. portable J instruments subject to shockit isbelieved 'th'at mechanical switching arrangements might be preferable to vacuum tube.switchingarrangements Mechanical switching, however, requires consideration of break of the. switch must bepositive. .at all times andthere must be'.no..mechanica1vibration ofathe switch. contact afterll theswitch has ..been.opene.d. In accordance. with. the presentiinvention. a switchingflarrangement has. been. provided which has taken. into consideration .the above. factors and which is used with aspaced ioopantennaar rangementlto.v provide, in effect, a double pole double Ithrow.v switching arrangement between the antenna and a direction-finder. receiven In addition. the switch also conuommitantlXreverses the connections to an indicating instrument and this reversal makes and breaks the, circuits subsequent to. and prior, to the, make and break of the doublepole double. throw switching arrangement. fl'hereiore, it is an object of the present in: vention to; provideaan improyediswitch particularly. suited ,for. switching radio. circuits. stil-if'anoth g.objection this invention is to provideanimproved motor...driven switch which is positive/in a'ctiqninmaking and breaking an cuits..and.which hasno vibratory action ofJthe Switch contacts.

The features oi this invention axesetforth with partiq leritni h tapnended claims. ther. and further. omensof;- this invention, willsubse que tlnbGQQIIlQ. ap arent bye eren e. in e Rowing descriptiqr taken. in. c qn nectionv with innah g swine whereintE si a t new, er aily f aken du 9 a switc .9 .1%1 h.e essstiq entivs B. R mless. Chica g a ssisn 9,

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.a lereta 2 time vi wsq he switch sh wn in Fig-- 93 t e im s-1:2: n 31s- 3 s a h maticarr nelme i .shc n thei onnecti ns etw n t es contacts. and: the e at qn betw he, cams tose herw h. heir s i tionsfinden ci it- Be er inetQ F s 1 and i heidrawingiihew is hawna switch contained n amu ng asframel L, af on pa L Z an 1a pm..

Iheh nt pan l .maxbe secured to. he am? l. bysu teble meansa ue as screws-lt- Ihe mn panel-su ports all ofthe sw tc centact lemems- The-ends oi he frame H a pr vided w h u t.- able bearin membe s 5.: whic supnq t a. cam shaft 16 having thereona plurality .ofadiustably positioned cams H-tg 22, inclusive, Theiatter twocams (a .ZZ-mfie i nst u n item the. other}. cams and. are sep at d. ye hielsi Z3 immthenther. cams The. cams. each pe at a. cam f llow upp r dadia en h ree.

end. 0.),- a. flat steel spring. 2 5 mounted in, an insulat s-block, assembly 5 wh ch iss curcd t0 th front panel .2: by suitable fastening... means .such as screwszl Each steel spring 25 isarranged to. actuate by...means,.0f an insulating spacer 28 arnickelssiiverspring: 2 9 ;having at an interme,- diate, point thereon a platinum, iridium contact 3.1-.- The lower. extremity. or the nickel lver spring, .2Q;is al osupportegi within the insulating black assembly 26.-an,d=is arrangedinph sical contact. with. anelectrical contact member 32 extendin through anjinsulating bushing. 33to theexterionoi the switch cabinet. A stationary adiustable...contact 34,015 platinum iridium is sup:- norted at .the end of a. threaded screw member 35 mounted in aninsulating lockorbushing 3. QXiQndingthrcugh the f rontspanel l's This construction reduces. to a. minimum the. capacity effect between the springZ-fl and the screw menib.er. 3;5. Adjacent the insulating block 3] thereis provideda connecting lug 38.1;etainedin position bythelock .nut '38; which .alsev retains in position the. adjusted. screw. .member. 326.. The. insulating members 31 '33 "and. 28. are. preferably of-I'a. ma;

* teriaL such. as. polystyrene, which. has. suitable electricalv insulating. and 1 power factor charac: teristicssothat aswitch maybe used: in radio Fre uency, ircuits.

hels'haftifi i Jarrsnsed-to be connected scan l ctric..motpnwhkh, in onefapmicatidn, is enerate ia afspe d RG/ 0R R- nter-Q rstoipr-Q: vid a aimm m orfrictiq between thercaml i8 and the spring 25 to be actuatedthereb y, it has island tie i ablet -pmv e ac m 1 w r 2.4. cthe...ie t xt taminf use roller-i elimination of friction reduces the possibility of introducing into the action of the spring 25 certain undesirable mechanical vibrations. Furthermore, the roller bearing reduces the generation of heat which otherwise would affect the operation of the steel spring 25. In order that the make and break of the contacts 3| and 34 be sharply defined, the movable contact 3| is located at an intermediate point on the cantilever portion of the nickel silver spring member 29. Furthermore, to insure simultaneous operation of a plurality of such contacts, the cooperating contact 34 is arranged to be adjustable. This permits an accurate determination of the making and breaking of each individual contact.

By referring to Fig. 3 it will be seen that the cams H to 20 are arranged to control make and break switch contacts 4| to 44, respectively, and that the contacts 4| and 42 are open when the contacts 43 and 44 are closed. These contacts are arranged in a circuit between a pair of spaced loop antennas 45 and 46 and a direction finder receiver 41. The switch contacts 4| to 44 are arranged to operate in the manner of a double pole double throw switch. In order that there be no interaction between the radio frequency circuit connected to the switch contacts 4| to 44 and the switch contacts 48 and 49 operated by the cams 2| and 22, there is provided the shield 23. The contacts 48 and 49 are connected between one terminal of the output circuit of the receiver 41 and an indicating circuit which includes a meter The meter 5| is connected across a pair of capacitors 52 and 53, the common juncture of which is grounded.

In the position shown in Fig. 3 it will be seen that the receiver 47 is connected to the loop antennas 45 and 46, It may now be assumed that the cam shaft is operating to rotate all of the cams in a clockwise direction. It will be noted that the next contact operation to occur will be the opening of the contact 49. Subsequent there- -to the contacts 43 and 44 will be opened and thereupon the contacts 4| and 42 will be closed so that the antennas 45 and 46 are reversed with respect to the input circuit of the receiver 41. After the contacts 42 and 4| have been closed the contact 48 will be closed. Prior to the opening of the contacts 4| and 42 the contact 48 again will be opened. Thus it is seen that the cams 2| and 22 operate to make and break the associated switch contacts 48 and 49 subsequent to and prior to the operation of contacts associated with the cams to 20. By having the cams 2| and 22 operate the associated switch contacts 48 and 49 in the manner described, the meter 5| is assured of proper indication in accordance with the energy received from the directional antennas. The capacitors 52 and 53 will each time be charged to a potential and a current flow will be established through the indicator tending to equalize the charges. on these capacitors if either one of thecapacitors receives a higher potential than the other. The meter 5| is a zero center instrument which will be deflected to the right or to the left to indicate as to whether the transmitting station has a bearing to the right or to the left of the position indicated by the directional antennas. The amount by which the indicator of the meter is deflected in any case is dependent upon the amount of deviation of the directional antenna from the bearing of the transmitting station.

While the cams H to 22 have been shown as having a particular coordination as indicated in Fig. 3 it, of course, is to be understood that when desired this relation may be changed since each of the cams is arranged to be adjustably positioned upon the cam shaft l6. Thus by adjustment of the cams upon the cam shaft l6 together with the adjustment permitted by the stationary switch contact, it becomes apparent that great accuracy may be obtained in the determination as to when the switch is to be operated.

It furthermore will be appreciated that while the present invention has been disclosed as applied to a direction finding receiving system, the switch is susceptible to applications in other fields where similar requirements must be met. The invention therefore which has been shown in a particular embodiment is not to be limited thereby since obviously variations may be made therein commensurate with the scope of the invention set forth in the appended claims.

What is claimed is:

1. An electric switch adapted to be motor driven comprising a container, a cam shaft housed therein and having a plurality of cams, said cams being arranged to actuate a plurality of switch contacts, each set of switch contacts comprising a flat cantilever steel spring supporting adjacent the free end thereof a, ball bearing cam follower, a movable cantileverspring insulated from and arranged parallel to said first spring member to be actuated thereby and having at an intermediate point thereon a switch contact, and an adjustable stationary contact supported by a member extending substantially perpendicular to the spring supporting said movable switch contact.

2. An electric switch adapted to be driven by a motor comprising a housing supporting therein a cam shaft having a plurality of cams, a pair of switch contacts for each cam including a flat steel spring member fixed at one end and provided adjacent the free end thereof with a ball bearing cam follower, another fiat spring member having one end fixed at a point spaced from the fixed end of said steel spring member arranged parallel to said first spring member, said other spring member carrying an insulating member arranged for continuous contact with said first spring member and supporting at an intermediate point thereon a movable switch contact, an adjustable stationary switch contact supported from said housing by a member arranged substantially at right angles to said spring members, and means for retaining said adjustable contact in adjusted position.

3. A shielded electric switch adapted to be driven by a motor comprising a shielded housing having a cam shaft, a plurality of cams for said shaft adapted to be adjustably positioned thereon, a circuit maker and breaker for each cam including a flat cantilever steel spring mounted upon a radio frequency insulator and arranged in a plane parallel to the longitudinal plane of said cam shaft, a roller bearing cam follower mounted adjacent the free end of said spring, a flat cantilever spring electric conductor mounted upon a radio frequency insulator and arranged parallel to said first spring, insulating means mounted. between the free ends of said springs t'c transmit movement from one spring to the other, an electric contact mounted at an intermediate point on said second spring, a radio frequency insulator supported by said housing parallel to said springs, a threaded electric conductor mounted in said latter radio frequency insulator substantially perpendicular to the plane of said electric conductor spring, and a contact mounted on the end of said electrical conductor for cooperation with the contact carried by said electrica1 conductor spring.

4. A shielded electric switch adapted to be driven by a motor comprising a shielded housing having a cam shaft, a plurality of cams mounted on said shaft, a circuit maker and breaker for each cam including a flat steel spring cantilever mounted upon a radio frequency insulator and arranged in a plane parallel to the longitudinal plane of said cam shaft, a roller bearing cam follower mounted adjacent the free end of said spring cantilever, a flat spring electric conductor cantilever mounted upon a radio frequency insulator and arranged parallel to said first spring cantilever, insulating means interposed between the free ends of said spring whereby a cam may impart simultaneous movement thereto, an electric contact mounted at an intermediate point on said second spring cantilever, an electric terminal connected to said second spring cantilever and extending through a radio frequency insulator to the exterior of said shielded housing, a radio frequency insulator supported by said housing parallel to said springs, a threaded electric conductor mounted in said latter radio frequency insulator substantially perpendicular to the plane of said spring cantilevers, a contact mounted on the end of said threaded electric conductor for cooperation with the contact carried by said electric conductor cantilever, and an electric terminal connected to said threaded electric conductor at the exterior of said housing.

5. A shielded electric switch adapted to be driven by a motor comprising a shielded housing having a cam shaft, a plurality of cams mounted on said shaft, a circuit maker and breaker for each cam including a fiat steel spring cantilever mounted upon a radio frequency insulator and arranged in a plane parallel to the longitudinal plane of said cam shaft, a roller bearing cam follower mounted adjacent the free end of said spring cantilever, a flat spring electric conductor cantilever mounted upon a radio frequency insulator and arranged parallel to said first spring cantilever, insulating means interposed between.

the free ends of said spring whereby 'a cam may impart simultaneous movement thereto, an electric contact mounted at an intermediate point on said second spring cantilever, an electric terminal connected to said second spring cantilever and extending through a radio frequency insulator to the exterior of said shielded housing, a radio frequency insulator supported by said housing parallel to said springs, a threaded electric conductor mounted in said latter radio frequency insulator substantially perpendicular to the plane of said spring cantilevers, a contact mounted on the end of said threaded electric conductor for cooperation with the contact carried by said electric conductor cantilever, and an electric terminal connected to said threaded electric conductor at the exterior of said housing, said cams being arranged in groups each individual to a different electric circuit, and shielded means mounted within said housing to separate said groups of cams.

6. A motor driven switch comprising, a shaft, a cam mounted on said shaft, an insulating block assembly, a cantilever steel spring secured in said block assembly and extending in the plane of said cam, a roller bearing follower mounted on the free end of said spring and bearing continuously on said cam, a second cantilever spring having one end secured in said block assembly and spaced from the fixed end of said first named spring, said second spring extending parallel to said first named spring, an insulating member secured to the free end of one of said springs and bearing continuously on the free nd of the other spring, a movable contact secured to an intermediate part of said second named spring, and a stationary contact mounted opposite said movable contact.

ROBERT P. DIMMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,121,996 Gassman Dec. 22, 1914 2,246,922 Macchioni June 24, 1941 1,993,957 Coberly Mar. 12, 1935 816,083 Farwell Mar. 27, 1906 2,094,337 Williams Sept. 28, 1937 912,447 Cofiee Feb. 16, 1909 1,036,700 Pfanstiehl Aug. 27, 1912 

